In a missile system, it is desirable to detect a potentially hostile airborne entity. It is also desirable to launch a missile against the entity if the entity is indeed hostile (also known as foe), and not to launch a missile against the entity if the entity is not hostile (also known as friendly).
A missile system may use radar to detect an airborne entity. For instance, the radar may provide data relating to the airborne entity such as speed, altitude, heading, time of measurement, range and/or bearing (where data may be considered to include position if range and bearing are included), etc.
It is noted that radar does not require the cooperation of an airborne entity in order to detect the entity, and therefore may detect the airborne entity even if the airborne entity does not cooperate. However, the data provided by the radar may not necessarily allow the detected entity to be sufficiently identified for the missile system to make a correct decision on whether or not to launch a missile against the detected entity. Moreover, the radar may not necessarily detect all airborne entity/ies. For instance, in some embodiments the radar may be limited in direction.
Optionally, the radar of missile system may include an Identification Friend or Foe (‘IFF’) system to interrogate an entity detected by the radar. If a response is received, the entity may be identified as friendly. However, it is possible that even if an entity is friendly, no IFF response or an incorrect response may be received, for instance because the entity does not have a transponder, because the entity's transponder is damaged, and/or because there are encryption problems, etc.